That setting is disabled, and been disabled for years on my system. I do have “Run a partial scan when changes are detected” and “Scan my library automatically” enabled. That works perfectly for TV and movies, but the new Plex music doesn’t seem to pay attention to those settings. Simply changing a folder image or changing a tag in one file sets of a neverending scan of the whole library.
Nevermind… I’m just repeating myself…
I’m also noticing this issue. Kicking off a full scan of my 20k+ track Music library whenever I make a change to one artist or album is causing my server to basically be in a constant state of scanning. I love all of the new music features, but there is surely a better way to check Unmatched music semi-regularly than starting an entire library scan so often.
You can be president of the club for seeing the problem. 
I’ve tried the “look for folders with more than 50 files” suggestion, and I’m sure every other possible suggestion to make Plex stop re-scanning. I guess I should only have “Top 40” albums in my library.
I went folder by folder by subfolder thru my entire Music Library.
Here’s what I found:
The server was shut down during this process. While I was digging through the library, I also corrected any filenames that did not strictly match the suggested method of “track# - Song Title” There was about 30 or so that had to be changed.
I was impressed that only three albums came up as “New Additions” with a duplicate of those with the “trash-can / not available icon”. None of those albums had actually been changed in any way, so that was not expected. Emptied trash, and the library seems to be in order.
A few hours later, I added a new album to the library. This set off another complete scan of the library. I was a little disappointed, but decided that because it was also a new Artist, that it may be because my settings for the server has “Run a partial scan when changes are detected” which states “When changes to library folders are detected, only scan the folder that changed.” Obviously, the folder that the music library is pointed to changed, because a new Artist was added.
The next day, I added another album to the library. This album was added to an Artist already in the library, so I expected since the change was a new sub-folder under the artist, that Plex would “Only scan the folder that changed” Instead, Plex stubbornly scanned the whole library, at least twice, according to the logs, the console view, and the alerts view.
The music library is on one drive, and pointed to only one folder on that drive. My TV and Movie libraries do not set off a scan of the complete library with my current settings, and they are pointed at multiple drives and folders. Those libraries appear to respect the settings, and only scan the folder that changed, and all activity on the server is virtually instantaneous in comparison.
This same, unneeded, repetitive scanning occurs with any change, including changing the embedded tags within a file, or adding poster artwork.
If this isn’t a bug, and that’s the expected behaviour, I would at least like to know why a complete scan is necessary on the Music library.
Any other suggestions? I’m at a loss - the only other possible problem is the fact that many albums can not be matched by MusicBrainz because they do not have an entry for them. In that case, they all rely on the data from the embedded metadata, don’t they?
Server Version: 1.18.2.2015 (Windows)
Web App Version: 4.12.2
In the last 1-1/2 to 2 hours, the server has scanned the entire music library 3 times. I have tried every possible suggestion to stop this unnecessary scanning, but have had no success. I’m attaching logs once again, in hopes someone will actually look at them, and give me either a solution to the problem, or the reason Plex has determined a full library scan is required for every change or addition to the music library.
Plex Media Server Logs_2019-11-08_06-56-40.zip (5.2 MB)
The three scans were initiated by:
The library file system is structured exactly the way it’s recommended for the new music system:
…Music
…/… Artist Name
…/…/ Album Title
…/…/… 01 - Track Title
All files are all tagged with the Album, Album Artist, Track Artist, Track Title, Track #, Genre, Date, etc. Files added to the library more than 2 months ago were tagged with MP3Tag, files added recently have been tagged by MusicBrainz Picard.
When a new album is added, it shows up almost instantly in the library, with all of the correct information. All of the tracks are “playable” on any app at that point. The repetitive scans of the library to prove that “nothing has changed” are redundant and extremely annoying and continue for sometime after that. The music library is scanned as part of the regular maintenance schedule in any event, so there’s another complete scan of the library that occurs regularly.
Finally, I do have about 350 albums that are “unmatched.” There is no entry at MusicBrainz for those albums. However, those albums are displayed correctly in Plex, with all of the basic and accurate information from the embedded metatags. I am slowly adding those “unmatched” albums to the MB database. If those albums are the cause of the problem, the matching needs to be turned a little, because they are likely going to be un-matchable for some time.
Thanks in advance for any assistance in this matter.
Updated to the latest version of the server : Plex Media Server 1.18.2.2029 hoping that this may have been fixed, even though it was listed in the release notes.
Apparently, fixing this problem is extremely low on the “to-do” list, it is not re-producible by the developers, or there is a reason that a full library is required for any change to the library that Plex doesn’t want us to know about.
It happens on both music libraries I have.
My “Test” library, created specifically to try and solve this problem, has only 11 artists, 20 albums, total of 134 tracks. All artists, albums, and tracks are listed on MusicBrainz. There are no “Unmatched” albums. File structure identical to the support articles suggested criteria. The unnecessary complete scan on this library takes only a minute or two because of it’s size, but it’s still a complete scan.
The “real” library can take anywhere from 10 minutes to an hour for the scan, depending on whatever Plex is doing when 1 (one) item is changed. Annoyingly, if I add two albums at the same, it appears that that sets off two complete scans, because two changes were detected in the library.
No logs attached, I don’t expect a response.
Do you have, or is it possible, for a Plex Passer to BYPASS everything new and improved to get back to old and stale (but working fine), rely only on Local Metadata, abandoning MusicBrainz in total? Like in another test library you would set up that way?
Yeah, I can probably do that, by changing the agents in the library.
The problem is, that will only affect the new additions to the library - they will use the new agent, the old items will still be matched by the old agent. That’s if the music scanner and agents work the same way they do for other libraries. Who knows, it seems to have a mind of it’s own a different set of rules. It might stop the full scan though.
Another problem I can foresee, is that if I remember correctly from other posts in the forum, the old scanner Plex Music Scanner and the old agent Last.fm are eventually going to be removed, and not an option for anyone. So I’m likely just postponing the inevitable.
I’ll try on a test library to see how it goes…
I’m suddenly in fear for my music. I await your results, on bended knee.
You can remain standing for a little while.
Changing the agent on my test library gives me the expected results, The new addition is the only item scanned. Well, sorta kinda. I added a new album to an artist already in the library, and it re-scanned all of that artists albums, but none of the other artists and albums in the library. That is probably how it’s always worked, so it updates the info for the artist.
OK… thx.
All 9 of those were added the other day - taking a total of about 15 seconds from discovery thru fully populated. I’d really hate for that to change.
Even with the new scanner and agent, the new additions are populated properly almost instantly, and I can play them right away on all of the clients I’ve tried. But the server and hard drive chug along thru the entire music folder until it’s done it’s thing, whatever that is. 
Right, gotcha.
When Eric joined the gang above - it was completely over in 15 seconds with no lingering side effects or behindthescenes footage being shot.
If it all changes at some point, we’re gonna need a blues man with special talent…:
…I gave Plex seven albums and now she’s tryin’ to give 'em back!
Server Version: Version 1.18.2.2041 (Windows)
I have 2 music libraries, a real one I actually use, and a test one to try to nail down this annoyance.
The test library has 14 artists, and 24 albums. All are found on MusicBrainz, all tagged with Picard for proper metadata, all albums are matched.
Added one new artist with one album to the test library, total of 12 tracks in MP3 format.
This set off a complete scan, not only of the test library, but the real library. 6 minutes and 30 seconds later, the scan of both libraries was complete. I’m certain every folder in both libraries was scanned, even with my very limited ability to decipher the logs.
To be clear, all that the server had to do was match and add 12 tracks in one album by one Artist to the library.
When the unnecessary complete scans were complete, I waited 10 minutes and added 6 episodes of the Walking Dead. My server is no speed demon, so it took 3 minutes and 25 seconds to complete, but that included matching the files, generating thumbnails, and the deep analysis of those files.
Again I ask:
I’ve pretty much stopped trying to add music to the library, only when a server update is available, and then give up till the next update. I’ve implemented every possible solution given, but the repetitive scanning continues.
I’m not sure I’m willing to call it a “user error” unless running Windows 10 home edition as a server is the mistake. (waiting for the usual remarks from apple and linux users 
)
Quick Solution: do not point the music library to the “Music” folder of the Windows user running a Plex server. (and probably any other folder shared over the local network)
I’m using the same server I’ve been using for years, with the music library pointed to the “Music” folder for me, the only user on the system. I have a couple of other computers on the network, and they are configured to share with each other. Again, I’m the only user on those computers. This worked well with the old music system. I could rip a CD, and transfer it over the network to the folder Plex monitors, and within a few seconds it was added to the library, and the scan was over.
For some reason, the new Plex Music doesn’t work that way. A scan of the complete library happened every time anything changed in the library.
Through a day of Google, I found that there is no way to turn off the generation of the “thumbs.db” file in Windows Home Edition when a folder is shared. The “better” editions of windows have that ability, but not the Home Edition.
Those thumbs are updated or re-created each time the folder is accessed, which sets off the repetitive scans, when you have the server set to update automatically when there are changes to the library.
I’ve searched through the support articles, and haven’t found anything suggesting this might be a dumb idea. I’m certain the old system didn’t have the same problem, or if it did, it handled it faster and better.
Hope this little piece of info helps at least one person.
Wow. Great detective work! I would’ve never thought of this.
I am avoiding the pre-defined folder structure in Windows like the plague. That’s probably why I never encountered something like this.
Glad you’ve found the culprit!
Thank you, sir,. One annoyance I hope is gone forever.
I am on Windows 10 Pro with a non-system music folder (B:\Music). Per your suggestion, I turned off the thumbs.db creation. I still get a full scan after editing or adding an album. Unfortunately this is not a fix.
You are correct. Even if turning off the creation of thumbs.db was a solution that worked on the Pro Edition, it’s actually a workaround, and not a fix.
The old scanner didn’t have that problem, so it’s a flaw with the new system. In fact, I found that by changing the agent and scanner for the music library back to the old settings of Plex Music Scanner and Last.FM the full scan didn’t occur.
Curious, is B:\Music a shared folder?
My day with Google found that’s part of the problem with thumbs.db.but there’s a lot more to it than just turning it off. I am supposed to be able to turn off the creation of thumbs.db in Home Edition, but the file is still generated for shared folders. If Widows explorer is used in any view other than list view, thumbs may be generated. If “Always show icons, never thumbnails” is not enabled, than the file might be generated.
Window Pro has some extra settings you can change in the registry that are not available Home Edition. I can’t say if those would work. You can also change some advanced settings regarding thumbs.db in the Group Policy Editor, another option not available for Home Edition. There are other steps to take, but they started t get way to “geeky” for me to even consider.
There is obviously something wrong with the new scanner, because the old system didn’t have the same problem. The average person isn’t going to take all the extra steps that might work as a “temporary” solution.
I’m hoping that my workaround might be a starting point for the Plex devs to actually fix the problem. The hard part is actually getting them to acknowledge that it’s a problem, and I haven’t seen that anywhere.
The latest blog post is about the “Awesome” new music system and boasts that “music matching and recognition is now super fast and super accurate” Anyone that’s changed the metadata for one file and waited an hour or more for the scanner to stop would disagree.
This topic was automatically closed 90 days after the last reply. New replies are no longer allowed.
